Pillow

ABSTRACT

A pillow ( 1 ) according to present invention comprises a body ( 3 ) including a concave portion ( 7 ) in a central part and a cold insulator ( 5 ) incorporated in the concave portion ( 7 ). The cold insulator ( 5 ) has a gel material enclosed in a bag member which is formed by an enclosing film. It is preferable that the body ( 3 ) should be formed of a rubber or a synthetic resin material and should have a flexibility and a restoring property for a deformation. It is more preferable that the gel material should be a hydrogel or a lipogel. Furthermore, a plurality of dents ( 9 ) is provided on the surfaces of the body ( 3 ) and the cold insulator ( 5 ). The pillow can hold and cool a head in such a shape as to conform to the shapes of a neck and a head, thereby casting no burden on a human body. A cooling function lasts long by the cold insulator ( 5 ) incorporated in the body ( 3 ). Plural kinds of cold insulators ( 5 ) to be incorporated can be retained and replaced, and can be regulated depending on a user and a situation.

This application claims priority on Patent Application No. 2003-312629filed in Japan on Sep. 4, 2003

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a pillow. More particularly, thepresent invention relates to a pillow to be used for cooling a head.

2. Description of the Related Art

Conventionally, a water pillow has been used for cooling a head of aperson. The water pillow is troublesome to replace ice or water. For thereplacement, a place, a vessel or the like for treating the water isrequired. In order to eliminate the troubles, various devises have beenmade. For example, Japanese Laid-Open Patent Publication No. 2002-330986has described a pillow in which a capsule requiring no water is put. Inplace of the ice, the capsule is cooled and filled in the pillow foruse.

Japanese Laid-Open Patent Publication No. 2001-297 has described apillow in which a cold insulator is accommodated in a pocket provided ona pillow cover. The cold insulator is put on the market. Since the coldinsulator takes the shape of a simple sheet, it is thin. The coldinsulator has a larger contact area with the air and a small coldinsulating capability.

Japanese Laid-Open Patent Publication No. 2001-198151 has described acooled type cooling package utilizing an endothermic reaction in thedissolution of salt in water. When a pillow is to be used, an isolatedcooling agent is mixed with the water and they are dissolved to startthe endothermic reaction. The endothermic reaction process is caused toprogress continuously for a long period of time by the gelation of saltwater to be a reactive product. The gel thus generated is used in thesame manner as the cold insulator.

SUMMARY OF THE INVENTION

The shape of a pillow which conforms to a cervical vertebrae in the samemanner as a stand-up posture is better because it does not cause a bodyto carry a burden. For this purpose, it is necessary to hold a stabilityand a comfort to sleep when a head is put on the pillow whilemaintaining the shape of the pillow formed to be constant. In order tomaintain the shape of the pillow, it is necessary to cause the pillow tohave a restoring property. Both the pillow and a package are deformedaccording to the motion of the head and have no shape holding functionin the same manner as a conventional water pillow. On the other hand, ifa shape holding capability is too large, a shape following property ispoorer so that the stability of the head and the comfort to sleep aredeteriorated. More specifically, a flexibility is required for thepillow in order to enhance the stability and the comfort to sleep. Inconsideration of the actual circumstances described above, it is anobject of the present invention to provide a pillow in which a head canbe held and cooled in such a shape as to conform to the shapes of a neckand a head so as not to cast a burden on a human body, the cooling canlast long and a comfort to sleep can be enhanced.

The present invention provides a pillow comprising a body including aconcave portion in a central part, and a cold insulator incorporated inthe concave portion, the cold insulator having a gel material enclosedin a bag member.

It is preferable that the body should be formed of a rubber or asynthetic resin material and should have a flexibility and a restoringproperty for a deformation.

It is more preferable that the gel material should be a hydrogel or alipogel.

It is further preferable that a plurality of dents should be provided onsurfaces of the body and the cold insulator.

This pillow can hold and cool the head portion in such a shape as toconform to the shapes of a neck and a head. Therefore, a burden is notcast on a human body. The cooling function of a cold insulator which isincorporated can last long. Moreover, plural kinds of cold insulators tobe incorporated can be retained and replaced. An adjustment can becarried out depending on a difference in the physical constitution anduses of a user.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a pillow according to an embodimentof the present invention,

FIG. 2(a) is a plan view of FIG. 1, FIG. 2(b) is a front view of FIG. 1,and FIG. 2(c) is a side view of FIG. 1,

FIG. 3 is a sectional view taken along a III-III line in FIG. 2,

FIG. 4 is a sectional view taken along a IV-IV line in FIG. 2,

FIG. 5 is a perspective view showing a pillow according to anotherembodiment of the present invention, and

FIG. 6 is a graph showing a change in a temperature which is obtainedwhen pillows according to an example and a comparative example are used.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will be described below in detail based on apreferred embodiment with reference to the accompanying drawings.

FIGS. 1 to 4 show a pillow 1 according to an embodiment of the presentinvention. The pillow 1 is formed by a body 3 and a cold insulator 5.The body 3 has a concave portion 7 for incorporating the cold insulator5 therein. The cold insulator has such a contour as to almost conform tothe shape of the concave portion 7 so as to be fitted in the concaveportion 7. More specifically, the cold insulator 5 is incorporated intoa central part in the longitudinal direction of the body 3. Thus, thebody 3 and the cold insulator 5 are combined to obtain the configurationof the pillow to be used.

The size of the body 3 is not particularly restricted but always has awidth L of 400 mm to 1000 mm, a depth W of 300 mm to 500 mm and a heightH of 10 mm to 190 mm. As will be described below, the shape of theconcave portion 7 is determined corresponding to the cold insulator 5 tobe formed in consideration of the figure of a person. The shape (mainlya height and a curved shape) of the cold insulator 5 to be incorporatedin the concave portion 7 is set in such a manner that the shape of thewhole pillow is smoothened in combination with the cold insulator 5.

It is preferable that the body 3 should have such a hardness as tosupport the head of a person and should have a flexibility and arestoring property. For this reason, it is preferable that a rubber or asynthetic resin material should be used for the body 3. The rubber to beused includes a natural rubber, an isoprene rubber, a butadiene rubber,a styrene-butadiene rubber, an acrylonitrile-butadiene rubber and thelike. The synthetic resin material to be used includes a thermoplasticelastomer belonging to a type such as polyurethane, polyester,polyamide, polyolefin, polystyrene, polyvinyl chloride, silicone,polybutadiene and the like, or a combination of plural kinds.

It is more preferable that the material of the body 3 should be apolyurethane foam because a flexibility and various hardnesses can beregulated. In particular, a polyurethane foam having a low repulsion isfurther preferable. The body 3 is obtained by molding these materialsthrough a molding method such as injection molding, blow molding orextrusion molding.

In the case in which a flexibility (which is also referred to as asoftness) of the cold insulator 5 is large and a shape holdingcapability is small, particularly, the body 3 is formed in such a mannerthat the cold insulator 5 is maintained within the range of apredetermined shape by the concave portion 7. For example, a materialhaving a comparatively small flexibility and a high shape holdingproperty is selected for the material of the body 3. Alternatively, amaterial such as a side wall forming the concave portion 7 may bepartially thickened and the shape of the concave portion 7 may bechanged with difficulty. Moreover, a material having a higher elasticmodulus than that of the material of the body 3 may be partiallyprovided around the concave portion 7.

The cold insulator 5 can be replaced and incorporated into the concaveportion 7 of the body 3 as will be described below. For this reason, theconcave portion 7 is formed in conformity to the shape of the coldinsulator 5. When plural kinds of cold insulators 5 formed separatelyhave a difference in a dimension, however, a slight clearance may beformed between the concave portion 7 of the body 3 and the coldinsulator 5 in order to absorb the error. Also in the case in which theclearance is not formed, the cold insulator 5 can be incorporated withinthe range of the flexibility because the body 3 and the cold insulator 5have flexibilities. In some cases in which the clearance is too large,the range of a predetermined shape cannot be maintained, for example,the sink of a head is too deep, which is not preferable.

The concave portion 7 of the body 3 is provided based on a position onwhich a rear head is mounted and a size in use. A curved surfaceconforming to a shape from a neck to a rear head when a person stands upis formed in the central part of the pillow 1. The shape of the curvedsurface is taken by both the body 3 and the cold insulator 5.

As is apparent from FIGS. 3 and 4, a portion of the body 3 in which therear head is positioned when a person puts a head has a height reduced.The portion on which a neck provided just above a shoulder is put has aheight increased. In the case in which the cold insulator 5 is large,this shape is mainly taken and held by the cold insulator 5. In the casein which the cold insulator 5 is small, a predetermined shape is mainlydefined by the shape of the body 3.

The body 3 has a flexibility capable of following a deformation in astate in which the cold insulator 5 is incorporated. A person having ahead put on the pillow 1 changes the direction of the head or shifts theposition of the head. In order to enhance the deformation followingproperty of the pillow 1, a material having a low repulsive elasticmodulus is preferable. In order to obtain a good feeling of use, thebody 3 including the concave portion 7 requires the deformationfollowing property to some extent. For this reason, it is necessary tohave a proper flexibility and restoring property and to distribute andsupport the weight of the head over the whole surface of the head.

It is preferable that the body 3 should have a plurality of dents 9 on asurface. The dent 9 prevents the adhesion of the head or the like to thebody 3 when the head of a person or the like is put on the pillow 1.More specifically, a clearance is formed between the head or the likeand the body 3. Since the clearance has a gas permeability, neither asticky feeling nor stuffiness is generated. The dent 9 is formed byproviding a groove, a hole, a projection or the like on a surface. Thepillow 1 illustrated in FIGS. 1 to 4 has a parallel groove in alongitudinal direction on a surface. The shape of the groove, that is, adepth, an interval or the like is taken in conformity to the propertiesof the body 3 and the cold insulator 5 in order to enhance the feelingof use.

The surface of the cold insulator 5 is formed in conformity to a curvedsurface from a nape to the rear head in a stand-up posture. The coldinsulator 5 is independently fabricated separately from the body 3.Plural kinds of cold insulators 5 can be prepared for one of the bodies3. More specifically, only the cold insulator 5 can be removed from thebody 3 and can be cooled or frozen. As long as the cold insulator 5 canbe incorporated in the concave portion 7 of the body 3, particularly, itcan be replaced with a cold insulator having a different shape, forexample, a different height (thickness), a different curved shape of asurface or the like. Moreover, it is also possible to prepare variouscold insulators 5 having different hardnesses and cold insulatingperformances of a cold insulating material. These can be selectedaccording to circumstances.

The size of the cold insulator 5 usually has a width N of 100 mm to 500mm, a depth M of 150 mm to 500 mm and a height P of 10 mm to 190 mm. Inorder to combine the cold insulator 5 with the body 3 to adjust theshape of the pillow 1, the shape of the pillow 1 is mainly adjusteddepending on the height of the cold insulator 5. The height of the coldinsulator 5 can be varied according to a distance among the depth of theneck portion of a user, a shoulder of the user lying down and a sidehead, and furthermore, the preference of the user.

The cold insulator 5 is fitted in the central part of the pillow 1 witha constant thickness, thereby forming a part of the pillow 1. The sidesurface of the cold insulator 5 is maintained to be protected from anoutside through the body 3 formed of a foam or the like. Since the foamof the side surface has a heat insulating function, a thermal conductionfrom the side surface of the cold insulator 5 is lessened. Accordingly,an area on the surface side of the pillow 1 to which a heat istransferred from the outside is relatively reduced with respect to thevolume of the cold insulator 5. By the combination structure of the coldinsulator 5 and the body 3, an excessive heat is transferred from theoutside to the cold insulator 5 with difficulty. Referring to the pillow1, therefore, a cooling time is prolonged.

The cold insulator 5 also has some shape holding capabilities whilesupporting the weights of the head and the neck. By this function, theburden of the neck can be decreased when a person puts a head on thepillow 1. If the shape holding property is too great, however, the coldinsulator 5 tends to be too hard. If the cold insulator 5 is too hard,the deformation following property becomes insufficient when thepositions of the head and the neck are shifted. In order to enhance thefeeling of use, the deformation following property is required to someextent. The cold insulator 5 has a flexibility capable of following adeformation. The cold insulator 5 has a proper flexibility and restoringproperty and can distribute and support the weight of the head over thewhole surface of the head. For a material, a gel material is preferable.

The cold insulator 5 is usually used at a surface temperature of 5° C.to 30° C. The surface temperature of the cold insulator 5 is preferably1° C. to 25° C., and more preferably, 12° C. to 20° C. There is selecteda gel material which is advantageous to uses for a long time at thistemperature.

Examples of the gel material include a hydrogel having water as asolvent and a lipogel having oil as the solvent depending on thesolvent. Examples of the hydrogel include polyacrylic acid, polyacrylate(sodium polyacrylate or the like), polyvinyl alcohol, polyvinylpyrrolidone, polyethylene oxide, sodium carboxymethyl cellulose,hydroxypropyl cellulose, hydroxyethyl cellulose, methyl cellulose,sodium alginate, xanthan gum, gum arabic, traganth gum, karayagum and amaleic anhydride copolymer. For example, polyacrylic acid having aweight-average molecular weight of approximately 1000000 to 5000000 issuitably used.

Examples of the lipogel include gels comprising polyurethane,polyolefin, polystyrene, silicone, polyethylene, polyester, a vinylacetate copolymer, polyvinyl chloride, neoprene and a polybutadienerubber. These polymers are used singly or in combination. Moreover, itis possible to give or regulate an elasticity by adding a softeningagent, a plasticizer, a filler or the like depending on the propertiesof these polymers.

The lipogel is prepared by crosslinking these polymers together withoil. For example, there are used 100 parts by weight of oil in which apolymer is dissolved at an ordinary temperature, 10 to 20 parts byweight of a polymer, and organic peroxide. For the oil, there is used aplasticizer, for example, vegetable oil such as olive oil or castor oil,mineral oil such as liquid paraffin or process oil, ester oil such asdiethyl sebacate, dioctyl phthalate, dioctyl adipate, ethyl cinnamate,ethyl phenylacetic acid, ethyl oleate or benzyl benzoate, or animal oilsuch as squalene.

Examples of the organic peroxide include lauroyl peroxide, acetylperoxide, benzoyl peroxide, methyl ethyl ketone peroxide, cyclohexanoneperoxide, t-butyl peroxybenzoate and dicumyl peroxide.

Referring to the hydrogel and the lipogel, the lipogel is preferablebecause it has a viscosity at a low temperature. In particular, apolyurethane gel is preferable because a pressure dispersibility, aworkability, a price and the like are balanced. A thermosettingpolyurethane gel is more preferable. The polyurethane gel is obtained byheating and curing a mixture of polyol and isocyanate. Examples of thepolyol include polyether polyol, polyester polyol, polycarbonate polyoland polybutadiene polyol. In particular, polyether type polyol is morepreferably used in respect of a softness and a restoring property.Examples of the isocyanate include MDI, TDI, IPDI, HDI, HMDI, PPDI andXDI.

These gel compacts are obtained by carrying out filling in a bag havinga predetermined shape formed by an enclosing film and crosslinking, forexample. The gel compact may be obtained by pouring into a metal mold,and carrying out extrusion molding by means of an extruder and thenperforming crosslinking. If the enclosing film is resistant to someexternal force, a gel material is not soaked therein and properties arenot changed by the gel material, there is no particular restriction. Forexample, the enclosing film is formed of polyurethane, polyethylene,polypropylene, polyester, polyethylene-terephthalate (PET),polybuthylene-terephthalate (PBTO), polyamide, polyvinyl chloride andpolyvinylidene chloride or the like. Moreover, their composite film oran aluminized film can also be used.

In the case in which the thermosetting polyurethane gel is used, apolyurethane film is suitable for the enclosing film. The polyurethanegel and the polyurethane film have excellent adhesive properties.Therefore, the film is rarely peeled from the gel. For this reason, thesurface condition of the cold insulator 5 is maintained uniformly andexcellent shape holding properties can also be obtained.

It is preferable that the enclosing film should have a thickness of 0.02mm to 1 mm. If the thickness is smaller than 0.02 mm, there is apossibility that the film might be easily broken, resulting in adeterioration in a durability. If the thickness is greater than 1 mm, aflexibility is poor and a person feels a hardness when his (her) headcomes in contact so that a comfort to sleep cannot be obtained.

It is preferable that the enclosing film should have a tensile strengthof 10N or more, an elongation at break of 200% or more and a tearstrength of 5N or more. In the case in which the tensile strength andthe tear strength are smaller than the values described above, there isa possibility that the durability might be deteriorated. If theelongation at break is smaller than 200%, a flexibility is low.Consequently, there is a possibility that the degree of freedom of adeformation might be too low. For this reason, the cold insulator 5conforms to the shapes of human necks and heads with difficulty and thecomfort to sleep tends to be deteriorated. If the elongation at break istoo small, moreover, the film restrains the deformation of the gelmaterial from being caused by a turn-over in bed or the like.Consequently, only the film bears a deforming force. In this case, astress concentration is easily generated on the film so that thedurability of the film is deteriorated.

It is preferable that the surface of the cold insulator 5 should have aplurality of dents 9. A groove, a hole, a projection and the like areprovided on the surface of the pillow 1 including the cold insulator 5.As shown in FIGS. 1 to 4, the cold insulator 5 has the samegroove-shaped dent 9 as that of the body 3. The shape of the dent 9 ofthe cold insulator 5 does not need to be identical to that of the dent 9of the body 3. By the dent 9, the cold insulator 5 has an airpermeability. In the cold insulator 5, when the head or neck of a persondirectly comes in contact with the cold insulator 5, a stuffiness can beprevented from being caused by the perspiration of the person.

The same armor cover as the body 3 can be attached as an armor for theenclosing film to the cold insulator 5. The material of the armor covermay be the same as that of a well-known cover. For the armor cover,there is used a natural fiber such as silk, cotton or wool or asynthetic fiber such as polypropylene, polyester, polyamide, polyvinylalcohol or polyvinylidene chloride. A nonwoven fabric, a woven fabric, aknitted fabric or the like constituted by these fibers is used. Inrespect of an enhancement in a touch, their layered product and a fabrichaving a high porosity are preferable. It is also possible to use anatural leather or an artificial leather for the armor cover. Thethickness of the armor cover or the like is taken into consideration soas not to lose the function of the concavo-convex shape of the surface.

In the case in which the head and the neck portion of the person are tobe cooled, it is preferable that a body temperature should be dropped by1° C. in two hours when the person is induced to sleep. When the pillow1 is used, the cold insulator 5 cooled previously in a refrigerator orthe like is embedded in the body 3. The cold insulator 5 effectivelycools the rear head and the neck which are put on the pillow 1. The coldinsulator 5 has an excellent cold insulating property because anexcessive heat is transferred with difficulty as described above.Accordingly, the cold insulator 5 lasts a cooling effect for a longperiod of time.

FIG. 5 is a perspective view showing a pillow 15 according to anotherembodiment of the present invention. The pillow 15 also comprises a body17 and a cold insulator 19. The body 17 has such a shape that the heightof a central part on which the head of a person is put is the smallest.The cold insulator 19 is embedded in the body 17 in such a shape as tocorrespond to a concave portion provided in the central part of the body17. The shape of a surface formed by combining the cold insulator 19 andthe body 17 conforms to the shapes of a neck and a rear head in thestand-up posture of a person.

The surface of the cold insulator 19 is provided with a plurality ofelliptical dents 21. The body 17 also has a concavo-convex dent, whichis not shown. In the same manner as in FIG. 1, a shape holding propertyand a flexibility are taken into consideration and the materials of thecold insulator and the body and the like are used. The pillow 15 canalso cool the head without casting a burden on a human body. Moreover,the cold insulator 17 can have an excellent cold insulating property anda cooling capability can last long, and furthermore, a comfort to sleepcan be obtained.

EXAMPLES

While the advantages of the present invention will be apparent fromexamples, the present invention should not be construed to be restrictedbased on the description of the examples.

Example

A rubber composition containing a natural rubber as a base material (100parts by weight of a natural rubber, 115 parts by weight of a filler, 4parts by weight of a softening agent, 5.5 parts by weight of zinc white,1.1 parts by weight of stearic acid, 5 parts by weight of a foamingagent, 2 parts by weight of sulfur, 0.9 part by weight of avulcanization accelerator and 0.6 part by weight of an antioxidant) wasput in a metal mold and was vulcanized and foamed at 150° C. for 10minutes, and was thus molded to manufacture a body comprising a concaveportion. On the other hand, a polyurethane film (a thickness of 0.1 mm,a tensile strength of 20N, a tear strength of 8N and an elongation atbreak of 220%) was laid over a metal mold having such a shape as tocorrespond to the shape of the concave portion of the body, and thetemperature of a polyurethane gel was raised to 50° C. and was poured inan amount of approximately 50 mm into the metal mold, and was filledwith a curing type polyurethane gel and was crosslinked for 30 minutesat 120° C., and the metal mold was cooled to take out a molded productso that a cold insulator was obtained. The cold insulator was combinedwith the body and was covered with an armor cover (for the body; 100%cotton). Thus, a pillow according to the example was obtained.

Comparative Example

As a comparative example, there was used a general flat pillow put onthe market which includes a cold insulator put on the market(manufactured by Dunlop Home Products Co., Ltd., trade name of “SoftSnow Pillow”, a thickness of 30 mm, a length of 190 mm and a width of340 mm) (which is fabricated by a polyurethane foam, a width of 550 mm,a depth of 380 mm and a height of 10 mm, having an armor cover made of100% cotton).

[Evaluation]

Testing method: A head was put and the surface temperatures of a neckand a cold insulator were measured by using MT-8 manufactured by GramCo., Ltd. A result is shown in FIG. 6. Furthermore, ten testers werecaused to use the cold insulator at 15° C. to carry out a functionalevaluation for a comfort, a feeling of a fitness and a feeling of astuffiness. An average value was calculated based on an evaluation infive stages (very good: 5, good: 4, normal: 3, bad: 2, very bad: 1) sothat a result in Table 1 was obtained. TABLE 1 Example ComparativeExample Comfort 4.5 3.4 Feeling of fitness 4.1 2.2 Feeling of stuffiness3.5 1.8

As shown in FIG. 6, in the pillow according to the example, a rise in atemperature after the start of use is smaller, and apparently, a coolingfunction lasts longer and is more excellent than the pillow according tothe comparative example. As shown in the Table 1, moreover, amanufacturing method according to the example has a higher evaluationthan a manufacturing method according to the comparative example. Fromthe result of the evaluation, the advantages of the present inventionare apparent.

The above description is only illustrative and various changes can bemade without departing from the scope of the present invention.

1. A pillow comprising: a body including a concave portion in a centralpart; and a cold insulator incorporated in the concave portion, the coldinsulator having a gel material enclosed in a bag member.
 2. The pillowaccording to claim 1, wherein the body is formed of a rubber or asynthetic resin material and has a flexibility and a restoring propertyfor a deformation.
 3. The pillow according to claim 1, wherein the gelmaterial is a hydrogel or a lipogel.
 4. The pillow according to claim 1,wherein a plurality of dents is provided on surfaces of the body and thecold insulator.